You will need to fill with synthetic axle lubricant GM P/N 1237826 (Canadian P/N 10953455), and if necessary, add enough limited-slip differential lubricant additive GM P/N 1052358 (Canadian P/N 992694), or equivalent to maintain the original ratio of 1.6L (1.69 qt.) of axle lubricant to 118 ml. (4.0 oz.) of limited-slip additive.
By BobGM Specialist
01/11/2022